"Preload" is often employed to eliminate unwanted play in bearing systems: For example, preload may be used to eliminate excessive motion from a vehicle suspension system. However, achieving the desired preload in conventional bushing/bearing pivot systems ordinarily calls for extremely high tolerance machining of the components and/or threaded assemblies, which adds significantly to the cost of fabrication and assembly.
Another problem with conventional shaft pivot designs is providing a simple but secure manner for anchoring the pivot shaft to the housing so as to eliminate unwanted rotation of the shaft; for example, the common practice of resorting to a keyed construction adds considerably to the cost and complexity of the assembly. Yet another disadvantage of conventional shaft-pivot designs is the exterior press-fit which is required to hold the bearings and/or bushings in place.